Celtic rainforest and ancient woodland indicator plants on an anthropogenic site at the Holy Loch, Argylll, Scotland

This study documents the floristic, bryological and rainforest lichen composition of a young, anthropogenic woodland at Holy Loch Nature Reserve (HLNR), Argyll. Although the woodland is no more than 75 years old and established on upper, roadside saltmarsh and on an adjacent, capped industrial landfill, it supports a species assemblage characteristic of hyper-oceanic temperate rainforest. Surveys conducted between 2022 and 2025 recorded many bryophytes and lichens, including several oceanic species such as Radula complanata, Riccardia palmata and Neckera complanata, alongside rainforest-associated lichens including Lobaria pulmonaria and Peltigera membranacea. Multiple vascular plant Ancient Woodland Indicators (AWIs), including Hyacinthoides non-scripta, Oxalis acetosella, Carex sylvatica and Stellaria holostea, were also present despite the site’s young age. A freshwater swamp and regenerating carr contribute to habitat heterogeneity. At least 700 higher invertebrates and vertebrates have so far been recorded as using this woodland. The coexistence of AWIs, oceanic bryophytes, rainforest lichens and high invertebrate diversity supports the interpretation of woodland at HLNR as a young but developing temperate rainforest. These findings highlight the ecological value of post?industrial landscapes and provide a rationale for the site’s designation as a Local Nature Reserve.